Question

此问题与Delete a network profile from wpa_supplicant.conf in Linux (raspbian).

有关

使用以下命令，我们可以将输出视为文件的内容，并删除匹配的SSID网络块。

cat network_block_eg.conf | sed -n '1 !H;1 h;$ {x;s/[[:space:]]*network={\n[[:space:]]*ssid="example"[^}]*}//g;p;}'

问题是如何将输出作为匹配模式（在本例中为network = {}）。

例如，命令应输出

network={
    ssid="example"
    proto=WPA
    key_mgmt=WPA-PSK
    pairwise=TKIP
    group=TKIP
    psk="not so secure passphrase"
    wpa_ptk_rekey=600
}

Answer 1

cat network_block_eg.conf | sed -n '/[[:space:]]*network={/ {:a; /}/! {N; ba;}; /ssid="example"/ p}'

Sed命令解释，-n抑制正常输出：

/[[:space:]]*network={/ { # in a line that matches start block pattern
  :a                      # 'a' label to jump to
  /}/! {                  # if pattern space not contains end block pattern
    N                     # read next line and add it to pattern space
    ba                    # jump back to 'a' label
  }
  /ssid="example"/ p      # now if pattern space contains your desired ssid, print it out
}

Answer 2

sed用于单个行的简单替换，s/old/new/，全部。对于其他任何事情你应该使用awk，因为所有那些疯狂的sed结构做的事情都比1980年代中期发明awk时已经过时了。

如果没有简洁，可测试的样本输入和预期输出，但很难说这个样本输入（来自https://w1.fi/cgit/hostap/plain/wpa_supplicant/wpa_supplicant.conf）：

$ cat file
# Default LLT value for this interface in milliseconds. The value used in case
# no value provided during session setup. Default is 50 msec.
# fst_llt is in 1..4294967 range (due to spec limitation, see 10.32.2.2
# Transitioning between states).
#fst_llt=100

# Example blocks:

# Simple case: WPA-PSK, PSK as an ASCII passphrase, allow all valid ciphers
network={
        ssid="simple"
        psk="very secret passphrase"
        priority=5
}

# Same as previous, but request SSID-specific scanning (for APs that reject
# broadcast SSID)
network={
        ssid="second ssid"
        scan_ssid=1
        psk="very secret passphrase"
        priority=2
}

# Only WPA-PSK is used. Any valid cipher combination is accepted.
network={
        ssid="example"
        proto=WPA
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP WEP104 WEP40
        psk=06b4be19da289f475aa46a33cb793029d4ab3db7a23ee92382eb0106c72ac7bb
        priority=2
}

你似乎要求的就是这么简单：

$ awk -v RS= -v ORS='\n\n' '/ssid="example"/' file
# Only WPA-PSK is used. Any valid cipher combination is accepted.
network={
        ssid="example"
        proto=WPA
        key_mgmt=WPA-PSK
        pairwise=CCMP TKIP
        group=CCMP TKIP WEP104 WEP40
        psk=06b4be19da289f475aa46a33cb793029d4ab3db7a23ee92382eb0106c72ac7bb
        priority=2
}

，相反的是简单地否定/ssid="example"/的测试：

$ awk -v RS= -v ORS='\n\n' '!/ssid="example"/' file
# Default LLT value for this interface in milliseconds. The value used in case
# no value provided during session setup. Default is 50 msec.
# fst_llt is in 1..4294967 range (due to spec limitation, see 10.32.2.2
# Transitioning between states).
#fst_llt=100

# Example blocks:

# Simple case: WPA-PSK, PSK as an ASCII passphrase, allow all valid ciphers
network={
        ssid="simple"
        psk="very secret passphrase"
        priority=5
}

# Same as previous, but request SSID-specific scanning (for APs that reject
# broadcast SSID)
network={
        ssid="second ssid"
        scan_ssid=1
        psk="very secret passphrase"
        priority=2
}

如果那不是您想要的，那么编辑您的问题以提供样本输入和预期输出，以澄清您的要求，我们可以进行测试，以便我们可以提供一个不同但仍然清晰和简单的awk解决方案。

使用SED实用程序输出匹配的模式而不进行替换

2 个答案: